The present invention relates generally to sheet feeder apparatuses, and more particularly to improvements for sheet feeders that are used to separate single sheets from a supply of sheets and then feed the separated sheets downstream for further operations, such as reading indicia off the sheets and then sorting the sheets according to the read indicia.
As recognized by those skilled in the art, operating sheet feeders at or near their maximum capability is critical for optimizing output and throughput. However, what may be maximum capability for one type of sheet may no longer be optimum for a second type of sheet. For example, at a given speed, the smaller the sheets, the more the sheets will pass a predetermined point per unit time. At some point, the number of sheets passing that point per unit time will exceed the rate at which the sheets can be processed downstream, causing errors, misfeeds, or other unwanted overload conditions.
As sheet feeders should be able to handle multiple sheet sizes on the fly to achieve maximum flexibility and cost control, a structure and control system for handling sheets of various types is required that will not overload a downstream operation.
Accordingly, there is room for improvement within the art of sheet feeder apparatuses and methods.
It is an object of the invention to provide a sheet feeder apparatus and method that can be continuously operated at or near maximum capability.
It is a further object of the invention to provide a sheet feeder apparatus and method that can be continuously operated at or near maximum capability while feeding documents of differing length.
It is yet a further object of the invention to provide a sheet feeder apparatus and method wherein worn components can be replaced quickly and by operators of minimal skill level.
These and other objects of the invention are achieved by a sheet feeder, comprising: a magazine subassembly for supporting a supply of sheets to be fed down a sheet path and feeding the supply of sheets towards the sheet path; a feed subassembly positioned on one side of the sheet path and for separating the outermost sheet from the supply of sheets; a singulator subassembly, spaced across the sheet path from the feed subassembly, and for assuring that only the outermost sheet of the supply of sheets is separated from the supply of sheets; a transport subassembly for feeding the separated outermost sheet downstream for further processing; and a control system, the control system determining the size of the sheet separated from the magazine subassembly and adjusting the speed of the feed subassembly and holding the speed for predetermined durations to provide for a predetermined sheet gap size between the separated sheet and the next sheet to be separated dependent upon the length of the separated sheet.
Also in accordance with this invention, a method for feeding sheets comprises the steps of: providing a supply of sheets; sequentially separating a sheet from the supply of sheets; feeding the separated sheet downstream; and controlling the size of a gap between sequential sheets based upon the length of the sheets.
A method for providing a singulator subassembly in a sheet feeder is also provided and comprises the steps of: providing a drive shaft; providing one or more self-contained pre-constructed removable conveyor assemblies; placing one or more of the self-contained pre-constructed removable conveyor assemblies on the drive shaft; and placing a removable end cap on the drive shaft to secure the one or more self-contained pre-constructed removable conveyor assemblies in position.
Some of the objects of the invention having been stated hereinabove, other objects will become evident as the description proceeds, when taken in connection with the accompanying drawings as best described hereinbelow.